One Galaxy Sample to Rule Them All: Halo Occupation Distribution Modeling of DES Year 3 Source Galaxies

Abstract

For the joint analysis of second-order weak lensing and galaxy clustering statistics, so-called $3\times 2$ analyses, the selection and characterization of optimal galaxy samples is a major area of research. One promising choice is to use the same galaxy sample as lenses and sources, which reduces the systematics parameter space that describes uncertainties related to galaxy samples. Such a ``lens-equal-source'' analysis significantly improves self-calibration of photo-z systematics leading to improved cosmological constraints. With the aim to enable a lens-equal-source analysis on small scales we investigate the halo-galaxy connection of DES-Y3 source galaxies. We develop a technique to construct mock source galaxy populations by matching COSMOS/UltraVISTA photometry onto {\sc{UniverseMachine}} galaxies. These mocks predict a source halo occupation distribution (HOD) that exhibits significant redshift evolution, non-trivial central incompleteness and galaxy assembly bias. We produce multiple realizations of mock source galaxies drawn from the {\sc{UniverseMachine}} posterior with added uncertainties in measured DES photometry and galaxy shapes. We fit a modified HOD formalism to these realizations to produce priors on the galaxy-halo connection for cosmological analyses. We additionally train an emulator that predicts this HOD to $\sim 2\%$ accuracy from redshift $z=0.1-1.3$ that models the dependence of this HOD on 1) observational uncertainties in galaxy size and photometry, and 2) uncertainties in the {\sc{UniverseMachine}} predictions.

15 pages, 7 figures, 1 table. Accepted by The Astrophysical Journal (Vol. 983 Iss. 2, id. 183)

References in corpus (26)

• EAZY: A Fast, Public Photometric Redshift Code
• 3D-HST+CANDELS: The Evolution of the Galaxy Size-Mass Distribution since $z=3$
• Dark Energy Survey Year 3 Results: Cosmological Constraints from Galaxy Clustering and Weak Lensing
• Detection of quiescent galaxies in a bicolor sequence from z=0-2
• UltraVISTA: a new ultra-deep near-infrared survey in COSMOS
• KiDS-1000 Cosmology: Multi-probe weak gravitational lensing and spectroscopic galaxy clustering constraints
• Assembly bias in the clustering of dark matter haloes
• Halo assembly bias and its effects on galaxy clustering
• The dependence of dark halo clustering on the formation epoch and the concentration parameter
• Dark Energy Survey Year 3 Results: Weak Lensing Shape Catalogue
• On Halo Formation Times and Assembly Bias
• The baryon fraction of LambdaCDM haloes
• The Weak Lensing Signal and the Clustering of BOSS Galaxies II: Astrophysical and Cosmological Constraints
• Environmental Dependence of Cold Dark Matter Halo Formation
• The cosmology dependence of galaxy clustering and lensing from a hybrid $N$-body-perturbation theory model
• Spatial Clustering of Dark Matter Halos: Secondary Bias, Neighbor Bias, and the Influence of Massive Neighbors on Halo Properties
• Hyper Suprime-Cam Year 3 Results: Cosmology from Galaxy Clustering and Weak Lensing with HSC and SDSS using the Minimal Bias Model
• Simulations and symmetries
• The BACCO simulation project: biased tracers in real space
• Environmental Effects on Real-Space and Redshift-Space Galaxy Clustering
• Photo-z outlier self-calibration in weak lensing surveys
• The cosmological dependence of halo and galaxy assembly bias
• Cosmological inference from emulator based halo model I: Validation tests with HSC and SDSS mock catalogs
• Evidence of Galaxy Assembly Bias in SDSS DR7 Galaxy Samples from Count Statistics
• Cosmology from Clustering, Cosmic Shear, CMB Lensing, and Cross Correlations: Combining Rubin Observatory and Simons Observatory
• Satellite galaxy abundance dependency on cosmology in Magneticum simulations